The present invention relates to a device for the protection of moving machine parts.
In a machine tool or other manufacturing machine, the moving parts, especially the drive parts, are generally required to be protected by a suitable device or movable appliance, which, following the movements of the machine, keeps the moving parts shut off from the outside environment in order to prevent accidents to personnel working on or near the machine, to prevent dirt or other objects from coming into contact with the moving parts, thus reducing machine efficiency, and to prevent damage due to splashing of lubricant or other material.
Various different types of protective devices are known. These include devices designed to cover an opening in a casing which houses moving machine parts, this opening expanding and contracting at least in a lengthwise direction while the machine is working. These devices comprise a set of flat covering plates which protect the working parts of the machine located in the housing.
In these known protection devices, the covering plates as a whole are able to move between an extended position in which the plates are lined up lengthwise and completely close the opening, thus covering the working parts of the machine, and a retracted position in which the plates are gathered up over one another.
To enable the linear extension and retraction movements of the plurality of covering plates, protection devices of this kind have separate lateral mounting blocks with grooves in them. The lengthwise edges of each plate are inserted into the corresponding grooves so that the plates can slide backwards and forwards in separate parallel planes.
The main drawbacks of a protection device of this kind, used for closing flat openings, stem from the large number of parts which it consists of. This is in itself a major disadvantage but is closely connected to another major disadvantage due to the fact that, to close an opening of variable size on working apparatus, a suitable number of mounting blocks must be fitted beforehand on the sides of the opening in a plane above that in which the opening itself lies. The resulting structure can be extremely bulky and, indeed, a protection device of this kind cannot be applied to working apparatus at all unless sufficient room is provided to accommodate these cumbersome, lateral mounting blocks.
Another serious disadvantage is that chips and swarf from machining operations tend to settle in the the grooves in the mounting blocks, causing the protection plates to jam and, in the long run, making the protection device unusable.
The present invention has for an object to overcome the above mentioned drawbacks.